Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Data Files
• Supplemental Files
• Related Publications
• Parameters
• Instruments
• Project Information
• Funding

Adult Americamysis bahia (hereafter, mysids) were purchased and shipped from Biosystems, Inc (Fort Collins, CO). Mysids were shipped acclimated to 15 ppt water salinity. Upon arrival at Chesapeake Biological Laboratory, mysids were acclimated to the experimental conditions of water temperature = 22 degrees C, and salinity = 14 ppt. Mysids were held for a minimum of 3 days prior to experimentation, during which period they were fed 1 day old Artemia nauplii ad libitum. 

Prior to experiments, mysids were fasted for 1 day to allow depuration of stomach contents and ensure mysids were actively searching for prey. During experiments, individual mysids were placed in a 1-L container with filtered, artificial seawater (Instant Ocean® Sea Salt, Blacksburg, VA) mixed to a concentration of 14 ppt. A total of 60 (Series 1) or 40 (Series 2) 1-day old Artemia nauplii were added to each container, sealed and placed on a slowly rotating, custom-made zooplankton grazing wheel. The wheel rotates very slowly around a central axis and is designed to keep plankton or zooplankton in suspension during grazing experiments. The experiment continued for 4 hours. Following each experiment, mysids placed in a petri dish and digitally measured for body length (rostrum to base of the telson) under light microscopy (CellSens imaging program, Evident Scientific). Containers were filtered using 40-micron nitex mesh and all remaining Artemia were enumerated. 

Microsoft excel was used to record and organize data, associated metadata, and create the plot attached as supplemental file. 

- Imported "20231108_Mysidsizeexperiments_22C_1mysid_Americamysis.xlsx" sheet 2 into the BCO-DMO system
- Added "Series 1" and "Series 2" values to a new parameter "Series" to differentiate the sample numbers
- Removed spaces and special characters from the parameter names, in compliance with BCO-DMO standards
- Exported file as "986238_v1_mysid_consumption.csv"

NSF Award Abstract:

Diagrams of food webs are typically drawn as boxes that show linkages between predators and prey. While these are useful models of how energy is transferred along a food chain, real food webs are more complex. Predator diets are often variable making it difficult to establish predator-prey links in marine communities. This project is investigating prey switching in a key member of coastal food webs, the shrimp-like mysid, Neomysis americana. Prey switching affects community structure and an organism’s resilience to environmental perturbation, but it is not easy to quantify. This project is using a combination of laboratory experiments and field sampling to develop a food web model that predicts mysid feeding patterns in the environment. This realistic and predictive food web model uses traditional gut analysis and analytical techniques that follow carbon and nitrogen as it is incorporated into the bodies of the mysids. In addition, mysid food preferences are being determined in the laboratory across a full range of diet possibilities. The calibrated gut analysis and chemical marker data in combination with feeding experiments are incorporated into the model, which then predicts mysid feeding on mixed diets under different environmental conditions. These predictions are validated against field data. Broader impacts include benefits to society for a better understanding of how coastal food webs work. Doctoral students and undergraduate students are being trained in experimental and field research. Increasing diversity in STEM fields is occurring through a partnership with two community colleges (College of Southern Maryland, Chesapeake College) to recruit summer interns for research experiences. Outreach activities include the development of educational materials for grade-appropriate hands-on laboratory experiments and training opportunities for middle and high school teacher groups in the use of these materials in their classrooms.

This project is developing and field-testing a generalizable approach to understand and predict complex predator-prey relationships in marine food webs. The research plan involves building and validating a multispecies functional response (MSFR) model for an omnivorous consumer, the mysid Neomysis americana. These models predict diet for consumers that feed on multiple types of prey under differing prey concentrations and identify conditions under which prey switching occurs in the environment. Recent and time-integrated diet tracking with gut contents, bulk stable isotope (SI) and compound-specific amino acid stable isotope (AA-CSI) analysis are validated in the lab and used to reconstruct diet of Neomysis in the field. The proposed research is testing specific hypotheses about Neomysis’ consumption rates and prey preferences and the effectiveness of integrating SI and AA-CSI into MSFR models. Laboratory experiments are determining prey-specific functional response curves by Neomysis under varying prey concentrations and environmental (temperature) conditions using grazing experiments. Experimental results are incorporated into a temperature-dependent MSFR model for a 5-compartment simplified food web (Neomysis, adult copepod, copepod nauplii, phytoplankton, detritus). A complementary element of the project is the experimental determination of bulk SI (𝛿13C and 𝛿15N) and AA-CSI (𝛿15N) equilibration rates and trophic enrichment factors for Neomysis and each prey type. The predator-prey dynamics of Neomysis in the environment are being modeled using the lab-validated MSFR approach and field data, including prey concentrations, gut contents, and prey and Neomysis SI and AA-CSI data.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.